Maybe one of both. Not sure.
https://www.ebay.com/itm/Yagi-Booster-For-DJI-Mavic-Models-And-Spark-Drone-Range-Antenna/283784129305?hash=item4212da2b19:m:mySmICnxqp3UQ_nG8dI1RTQ
Turn on both the mini and controller. Press the power button on the controller for about 5 seconds until it beeps. Press the power button on the mini for about the same amount of time and the two will pair.
Just received my 5.8 ghz Yagi antenna from Slovenia and it definitely increased range and aids in video transmission. Better than the foiled reflectors. I live in a rural area with little interference so can't comment on urban improvement.